Rose, the Doctor, and the Dementors
by circlet
Summary: Rose and the Doctor were just exiled from Victorian London when suddenly, the TARDIS spins out of control, landing them in Harry Potter's third year. Mystery, romance, adventure and running await in this crossover AU. Pairings: TenRose, Romione This is my first-ever fanfic, so (constructive) criticism is appreciated! Thank you!
1. Chapter 1

Chapter One: Werewolves to Willows

Exiled, from her own country, centuries before she was born. After being knighted by Queen Victoria, no less! And of course, Rose couldn't forget the werewolf. It all seemed so mad, and no one would believe her back home, but maybe they didn't need to. After all, she had the Doctor. The only one that would ever understand.

"Well, maybe hemophilia is just a Victorian euphemism," the Doctor said.

Rose stopped short. The Royal Family, werewolves? It couldn't be!

"Nah, that's just ridiculous!"

"I'll say no more…" The Doctor grinned.

Rose laughed. "They plan everything in advance! They could schedule themselves around the moon, we'd never know!"

Laughing, the two travelers stepped into the TARDIS. The change of size didn't even bother Rose anymore. Why can't it be bigger on the inside? This ship was starting to feel like home, even more than her flat. She leaned against the TARDIS console, still smiling.

"So, where to next?" the Doctor asked Rose in that infuriatingly hyper way. "We could still catch that concert, if you like."

Where to next, that was the question. She could go anywhere, anytime. Visit London five hundred years ago, or see it five hundred years in the future. The most distant stars and planets were all hers to observe. She could even visit her father, _probably best not to try_ that _again,_ Rose thought.

"Well-"

Before Rose could finish her sentence, the TARDIS glowed red. The central column churned, and deafening alarms sounded. She tried to catch her balance, but the ship spun and jerked, throwing her to the floor. Rose pulled herself up and turned to face the Doctor, confusion and fear on his face as he tried to steady the ship.

"Doctor? What can I do?"

"Hold down the dimensional loop- no, not there- there! That should hold us-"

The TARDIS heaved again, and Rose lost her balance, letting go of the loop.

"Whatever I do, the ship doesn't respond! We're being dragged through dimensions, and there's nothing I can do!" The Doctor kicked the console. His eyes widened, and he looked at Rose. "It's almost like… _magic._ "

At this, the TARDIS powered down, shuddering to a stop. Rose breathed a sigh of relief. Wherever they were, they would be absolutely safe. Nothing could penetrate the TARDIS walls, not even a Dalek death ray. All she and the Doctor had to do was to stay inside.

WHAP!

The TARDIS slammed to the left, then right again. An enormous branch punched through the wall just above the door, swinging back and forth an inch from her head. Rose staggered back.

 _Great,_ thought Rose. _Second time I've been nearly killed by a tree._

The Doctor clung to a rail. "Magic? But that's impossible, it can't be. Sure, werewolves, ghosts… but they're all aliens! This- this is human. Magic's just something you read about in books, it can't possibly be real…"

With the TARDIS still being pulverized by this murderous tree, the Doctor made his way to the door, inching along the rails. He lurched forward, grabbing the door handle for stability.

"Doctor, watch out!" Rose cried.

He opened the door, astonished. He turned back to Rose, about to tell her the news when the branch inside the TARDIS swung down. He dodged it, and ducked down to meet Rose.

"Out! Out now!" He grabbed Rose's hand and pulled them to the door. "Jump!"

Rose didn't see how a four meter drop was worse than death by tree, so she sprung out of the TARDIS, landing on her side. The Doctor was already on his feet, and staring into the distance. He pulled Rose up, and gestured for her to look ahead. She saw a castle, with sand green spires that stretched into the crisp afternoon sky. A lake bubbled to its side, and- was that a giant squid? It seemed familiar to her somehow, but she couldn't quite place it.

"Rose," the Doctor sounded strangely excited. "Welcome to Hogwarts."


	2. Chapter 2: Introductions and Insights

"I swear, Hermione, your cat's got it in for Scabbers! The poor rat's fur is falling out. He's going to die of fright!"

"Ron, really, Crookshanks is a cat! He doesn't know any better. If you're so scared of him dying, then why don't you take better care of him?"

"I do!"

Harry stared straight ahead as his friends bickered on either side of him. This argument had been going ever since Hermione brought home her squashed orange cat from Diagon Alley. He wished they'd just stop and he could have some peace.

Ron and Hermione still at each other's throats, the trio walked down to Hagrid's house. Harry was determined not to add to the tension with his dementor troubles.

Harry put up his hands, silencing his friends. "Who-" He pointed toward the Whomping Willow. "-are they?"

"I dunno," said Ron, leaving the cat vs. rat argument. "New teachers? Why's she wearing overalls?"

"They must have apparated in," said Harry. He and Ron rushed ahead to investigate the bewildered visitors.

"How many times do I have to tell you?" Hermione said, exasperated as she jogged to catch up. "You can't apparate in or out of Hogwarts. Honestly, do you boys even read?" She stopped short in front of the time travelers, nearly plowing into Rose.

Rose nudged the Doctor, but he was still looking around in awe. She sighed, and introduced them. When Hermione was about to respond, the Doctor snapped out of his daydream. "Oh no, don't tell me. The Golden Trio, it's always you three. The brightest witch of her age-" Hermione looked rather flattered, "-the chosen one-" Harry grinned. He _was_ the chosen one, after all, "and our king!" Ron looked around- could he have meant that for someone else? The Doctor studied the three, finally stating, "Third year, Sirius Black's on the loose, and there's a nice bit of time travel towards the end. Loved that bit, never saw it coming." The Doctor looked at Harry and Ron, amused. They stared back with complete confusion. "Hogwarts, eh? Oh, this is brilliant! Rose, didn't I always tell you how much I wanted to come here?"

Rose was skeptical. Sure, Hogwarts was great, but it was _fictional_. She'd caught bits of the movies on the telly, but that's all. It was impossible for them to be here.

"But, Doctor, I hate to ruin this, but we can't be here. Hogwarts doesn't exist."

"Well, of course it doesn't! Not in our universe, anyway. But J.K. was so brilliant, she tapped into a parallel universe to write her books. Hogwarts exists here just as much as you and I in our universe. We must have jumped a dimension when the TARDIS… well, apparated."

Rose shrugged. She'd faced Daleks and ghosts, surely she could survive a day with witches and wizards.

Hermione cut in, "Excuse me, it was nice meeting you, but we've got to go! I've got my Arithmancy exam at nine, and Harry and Ron have Divination." She glanced at the boys, who were about to protest.

Rose waved them away, Hermione walking at a determined pace up the hill, leaving Harry and Ron to anxiously look behind them as they hurried after her. Rose turned to the Doctor, about to process this turn of events. The Doctor stared after the trio, saying, "Did they just say their Divination exams?"

"Yeah. Does it matter?"

The Doctor turned to face Rose. "Harry's Divination exam. It's when Sybil Trelawney made her first real prediction. Well, second. Her first was-" His face brightened as it usually did when he explained something from his many fandoms. Rose usually enjoyed these, but today, they didn't have time.

"Doctor?" said Rose, exasperated. "Why's Divination so important?"

"It's when those three meet Sirius Black!"


	3. Chapter 3: Footprints and Follies

"Could this all be connected? The TARDIS crashing and this prophecy?" Rose asked.

"Of course it's connected, we just don't know how!" The Doctor paced nervously. "Whatever hijacked the TARDIS might be threatening Hogwarts."

Rose turned around to face the Whomping Willow. The TARDIS was relatively unharmed, and they would be able to reach it if the tree wasn't swinging it so violently. If only there was a way to stop it…

"Doctor? You might want to see this…"

A cat swerved between the branches, tapping a knothole with its paw. The tree shuddered to a stop, a few branches dangling aimlessly in the breeze.

"Crookshanks!" The Doctor whirled to Rose and grabbed her hand. "You brilliant cat!"

The two travelers rushed to the tree, and climbed back into the TARDIS. Laughing, Rose pulled the Doctor up.

"Now!" exclaimed the Doctor, rubbing his hands together, "I'd say this was a basic Summoning charm, accio and all that, except it would take a lot more than that to hijack a TARDIS. Powerful, powerful stuff, to pluck us out of our dimension." He bent down to examine the console's underside. "Everything seems alright. We're just… stuck." The Doctor shook a lever back and forth to no avail, and kicked the console as hard as he could.

"But why?" Rose said over the Doctor's "Ow!".

The Doctor leaned onto the rail. "Haven't got a clue. Maybe-"

He glanced at the console. "Seven o'clock! We need to get out of here, we can't affect their timeline…"

They scrambled out of the TARDIS, and ran to hide behind Hagrid's hut.

There was a knock at the door. Rose peeked around the side of the house, but the Doctor pulled her back. "It's just Harry, Ron and Hermione. Nothing to worry about quite yet…" he whispered.

A shriek echoed from the inside. The Doctor turned to Rose. "Hermione just found Scabbers. That means…"

There was a shuffling at the back door. "Run!"

Harry, Ron and Hermione followed Hagrid out the door, and huddled under the invisibility cloak. Rose and the Doctor ran to the edge of the forest, making sure to stay in the shadows of the darkening sky. Just as they caught their breath, a group of men descended the distant castle steps.

"They're coming to execute Buckbeak-" Rose's eyes widened, and she made a start for the pumpkin patch where the hippogriff was tethered, but the Doctor held her back. "No, no, no, we can't interfere! Anyways, it'll all come right in the end… I think."

Rose found it hard to see in the blackening sky, but she watched a trail of faint footprints returning to the castle. The footprints stopped abruptly, and among a flurry of elbows escaping the cloak, a rat scampered away. Suddenly, Ron emerged from the darkness, sprinting after a cat. Harry and Hermione soon followed… to a particularly violent tree. "Doctor! Something just dragged Ron _into the tree_!"

The Doctor watched, finding it hard to concentrate while Rose held his hand. _This is NOT the time!_ "Right… it's later than I thought." His hand suddenly felt empty. He turned to where Rose stood, but he only saw trees. Panic setting in, he saw a pink blur rushing toward the Whomping Willow. "Rose!"

She looked over her shoulder. "They need help!"

The Doctor shook his head and sighed. And ran after her.

Sorry I haven't been updating much, school's been hectic. Thanks for waiting!


End file.
